Transmission and vehicle having transversely mounted transmission and engine arranged in axial direction thereof

ABSTRACT

A vehicle includes an engine, a pair of side frames extending along a vehicle body in front-rear direction of the vehicle, a transmission adapted to be axially connected with the engine and adapted to be transversely mounted on a vehicle body, includes an input shaft, a first counter shaft, a second counter shaft, a first gear mechanism, a second gear mechanism, a third gear mechanism, and a transmission case, wherein the first and third gear mechanisms are arranged close to the engine, the second gear mechanism is arranged more distant from the engine, the second counter shaft is arranged above the input and the first counter shaft, and the transmission case forms a cut-out portion at an upper portion of the back wall portion of the transmission case.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. §119 toJapanese Patent Application 2007-235821, filed on Sep. 11, 2007, theentire contents of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a vehicle having an engine and atransmission that are connected to each other in an axial directionthereof and that are transversely mounted on the vehicle relative to avehicle body.

BACKGROUND

In order to downsize a transmission and increase output torque, forexample, a transmission apparatus disclosed in JP2002-70960A, adapted toa front-engine front-drive type vehicle to which an engine and atransmission connected in an axial direction thereof are transverselymounted, includes an input shaft, two counter shafts and plural shiftstage gear sets that are arranged in parallel to each other between theinput shaft and each of the counter shafts, thereby shortening length ofthe transmission apparatus in an axial direction thereof withoutreducing number of shift stages. A transmission 1 illustrated in FIG. 4has substantially the same structure as the transmission apparatusdisclosed in the second embodiment of JP2002-70960A. As illustrated inFIG. 4, an input shaft 3 a, first counter shaft 3 b, a second countershaft 3 c and a reverse shaft 3 d are arranged in parallel to each otherwithin a transmission case 2. The first counter shaft 3 b and the secondcounter shaft 3 c are connected to output shafts 8 a and 8 b viareduction gear set 6 a, 6 b and 6 c and a differential mechanism 7. Afirst forward movement gear switching unit 4A forming a 1st shift stageand a 2nd shift stage and a second forward movement gear switching unit4B forming a 3rd shift stage and a 4th shift stage are arranged betweenthe input shaft 3 a and the first counter shaft 3 b so that the secondforward movement gear switching unit 4B is positioned farther away froman engine 10 than the first forward movement switching unit 4A. A thirdforward movement switching unit 4C forming a 5th shift stage and a 6thshift stage is arranged between the input shaft 3 a and the secondcounter shaft 3 c so as to be located at a position substantiallycorresponding to the position where the second forward movement gearswitching unit 4B is arranged, in an axial direction of the input shaft3 a. Further, a reverse movement gear switching mechanism 4D forming areverse shift stage is arranged between the input shaft 3 a, the secondcounter shaft 3 c and the reverse shaft 3 d so as to be located at aposition substantially corresponding to the position where the firstforward movement gear switching unit 4A is provided, in the axialdirection of the input shaft 3 a. A back wall portion 2 a of thetransmission case 2, substantially corresponding to an area where inputshaft 3 a, the first counter shaft 3 b and the second counter shaft 3 care arranged orthogonally relative to the back wall portion 2 a, isformed to have a flat surface.

FIG. 5 schematically illustrates a forward portion of the vehicle,viewed in a lateral direction thereof, to which a driving unit istransversely mounted at the forward portion of a vehicle body. Thedriving unit is a unit in which the transmission 1 disclosed inJP2002-70960A is connected to the engine 10 in an axial directionthereof. As illustrated in FIG. 5, the driving unit is positionedbetween a pair of side frames 9 extending along both sides of thevehicle body in a front-rear direction thereof. In order to prevent theside frames 9 from interfering with a front axle, forward portions ofthe side frames 9 are curved upwardly. Hence, as illustrated in FIG. 5,the side frame 9 at the left side in FIG. 5 extends along immediate leftof an upper portion of the back wall portion 2 a of the transmissioncase 2 in the front-rear direction of the vehicle.

In order to increase collision safety and vehicle stiffness, across-section of each of the side frames 9 needs to be enlarged and ashape of each of the side frames 9 needs to be linearized. The sideframes 9 a having the enlarged cross-section and the linearized shapeare illustrated with chain double-dashed lines in FIG. 5. As is evidentfrom the position of the side frames 9 a having the enlargedcross-section and illustrated with the chain double-dashed lines in FIG.5, the side frame 9 a at the left side in FIG. 5 interferes with anupper left portion of the back wall portion 2 a of the transmission case2, and the side frame 9 a at the right side in FIG. 5 is positionedcloser to the engine 10. Hence, the driving unit having axiallyconnected engine 10 and transmission 1 may have difficulties when beingtransversely mounted on the vehicle body. A case where the driving unit,in which the engine and the transmission are connected in the axialdirection thereof, is adapted to the front-engine front-drive typevehicle is described above. However, as is the case with thetransmission adapted to the front-engine front-drive type vehicledescribed above, in a case where a similar driving unit is adapted to arear-engine rear-drive type vehicle, the driving unit in which thetransmission 1 and the engine 10 are connected in an axial directionthereof may have difficulties when being transversely mounted on thevehicle body because of the similar reasons explained above.

The transmission apparatus disclosed in JP2002-70960A suggests amodified transmission apparatus in which a portion of the back wall ofthe transmission case positionally corresponding to the second countershaft is arranged closer to the engine, compared to a portion of theback wall positionally corresponding to the first counter shaft byeliminating one shift stage. However, in the transmission apparatusdisclosed in JP2002-70960A, the portion on the back wall, correspondingto the second counter shaft and positioned closer to the engine thanother portions of the back wall, is positioned at lower portion of thetransmission case, thus resulting in creating a dead space at the backwall portion of the transmission case. Hence, even with the modifiedtransmission apparatus disclosed in JP2002-70960A, the driving unit mayhave difficulties when being transversely mounted on the vehicle.

A need thus exists for a vehicle which is not susceptible to thedrawback mentioned above.

SUMMARY OF THE INVENTION

According to an aspect of the invention, a vehicle includes an engine, apair of side frames provided at the vehicle so as to extend along bothsides of a vehicle body in front-rear direction of the vehicle, atransmission adapted to be axially connected with the engine and adaptedto be transversely mounted on a vehicle body, includes an input shaftadapted to be rotatably driven by the engine, an output shaft connectedto a driving wheel, a first counter shaft arranged in parallel to theinput shaft and connected to the output shaft, a second counter shaftarranged in parallel to the input shaft and connected to the outputshaft, a first gear mechanism arranged between the input shaft and thefirst counter shaft, the first gear mechanism having a first gear set,optionally a second gear set, and a first switching clutch toselectively establishing a power transmission path between the inputshaft and the first counter shaft via the first gear set or, if presentthe second gear set, a second gear mechanism provided between the inputshaft and the first counter shaft the second gear mechanism arranged inparallel with the first gear mechanism in an axial direction of theinput shaft and having a third gear set, optionally a fourth gear set,and a second switching clutch selectively establish a power transmissionpath between the input shaft and the first counter shaft via the thirdgear set or, if present the fourth gear set, a third gear mechanismbetween the input shaft and the second counter shaft, the third gearmechanism having a fifth gear set, optionally a sixth gear set, and athird switching clutch to selectively establish a power transmissionpath between the input shaft and the second counter shaft via the fifthgear set or, if present the sixth gear set, and a transmission casesupporting and covering the input shaft, the first counter shaft, thesecond counter shaft, the output shaft, the first gear mechanism, thesecond gear mechanism and the third gear mechanism, wherein the firstgear mechanism and the third gear mechanism are arranged relativelyclose to the engine, the second gear mechanism is arranged at a positionmore distant from the engine than the first gear mechanism, and thesecond counter shaft is arranged above the input shaft and the firstcounter shaft, and the transmission case includes a back wall portionlocated at a position spaced from the engine and formed with a firstback wall portion aligned with the first gear mechanism and the secondgear mechanism and a second back wall portion corresponding to the thirdmechanism and located closer to the engine than the first back wallportion, thereby forming a cut-out portion at an upper portion of theback wall portion, and wherein the transmission is connected to theengine and transversely mounted on the vehicle body so that one of sideframes extending along both sides of the vehicle body in a front-reardirection thereof extends through the cut-out portion, either a drivinggear of the second gear set arranged close to the second gear mechanismrelative to the first gear set at the first gear mechanism and providedat the input shaft, or a driving gear of the fourth gear set arrangedclose to the first gear mechanism relative to the third gear set at thesecond gear mechanism and provided at the input shaft serves also as adriving gear of the fifth gear set arranged at a position more distantfrom the engine relative to the sixth gear set at the third gearmechanism.

According to another aspect of the invention, a transmission adapted tobe axially connected with the engine and adapted to be transverselymounted on a vehicle body, includes an input shaft adapted to berotatably driven by the engine an output shaft connected to a drivingwheel, a first counter shaft arranged in parallel to the input shaft andconnected to the output shaft, a second counter shaft arranged inparallel to the input shaft and connected to the output shaft, a firstgear mechanism arranged between the input shaft and the first countershaft, the first gear mechanism having a first gear set, optionally asecond gear set, and a first switching clutch to selectively establish apower transmission path between the input shaft and the first countershaft via the first gear set or, if present the second gear set, asecond gear mechanism provided between the input shaft and the firstcounter shaft the second gear mechanism arranged in parallel with thefirst gear mechanism in an axial direction of the input shaft and havinga third gear set, optionally a fourth gear set, and a second switchingclutch selectively establish a power transmission path between the inputshaft and the first counter shaft via the third gear set or, if presentthe fourth gear set, a third gear mechanism between the input shaft andthe second counter shaft, the third gear mechanism having a fifth gearset, optionally a sixth gear set, and a third switching clutch toselectively establish a power transmission path between the input shaftand the second counter shaft via the fifth gear set or, if present thesixth gear set, and a transmission case supporting and covering theinput shaft, the first counter shaft, the second counter shaft, theoutput shaft, the first gear mechanism, the second gear mechanism andthe third gear mechanism, wherein the first gear mechanism and the thirdgear mechanism are arranged relatively close to the engine, the secondgear mechanism is arranged at a position more distant from the enginethan the first gear mechanism, and the second counter shaft is arrangedabove the input shaft and the first counter shaft, and the transmissioncase includes a back wall portion located at a position spaced from theengine and formed with a first back wall portion aligned with the firstgear mechanism and the second gear mechanism and a second back wallportion corresponding to the third gear mechanism and located closer tothe engine than the first back wall portion, thereby forming a cut-outportion at an upper portion of the back wall portion, and wherein thetransmission is connected to the engine and transversely mounted on thevehicle body so that one of side frames extending along both sides ofthe vehicle body in a front-rear direction thereof extends through thecut-out portion, either a driving gear of the second gear set arrangedclose to the second gear mechanism relative to the first gear set at thefirst gear mechanism and provided at the input shaft, or a driving gearof the fourth gear set arranged close to the first gear mechanismrelative to the third gear set at the second gear mechanism and providedat the input shaft serves also as a driving gear of the fifth gear setarranged at a position more distant from the engine relative to thesixth gear set at the third gear mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and additional features and characteristics of the presentinvention will become more apparent from the following detaileddescription considered with the reference to the accompanying drawings,wherein:

FIG. 1 is a view schematically illustrating an entire structure of anexample of a transmission adapted to a vehicle in which axiallyconnected engine and transmission is transversely mounted;

FIG. 2 is a view schematically illustrating the transmission viewed fromthe left side in FIG. 1;

FIG. 3 is a view of a portion of the vehicle, viewed in lateraldirection thereof, at which the axially connected engine andtransmission is transversely mounted;

FIG. 4 is a view schematically illustrating an entire structure of anexample of a conventional transmission; and

FIG. 5 is a sectional view of the vehicle, viewed in lateral directionthereof, at which the axially connected engine and the conventionaltransmission transversely mounted.

DETAILED DESCRIPTION

An embodiment of a transmission and a vehicle, to which the transmissionand an engine connected in an axial direction thereof will be describedbelow in accordance with FIGS. 1 to 3 of the attached drawings. FIG. 3schematically illustrates a sectional view of a forward portion of thevehicle, viewed in lateral direction thereof, in a case where theaxially connected engine and transmission of the embodiment is adaptedto a front-engine front-drive type vehicle. An engine 10 and atransmission 11, connected with each other in the axial directionthereof, are transversely mounted between forward portions of left andright side frames 13 that serve as primary strength members and thatextend along the both side portions of a vehicle body in a front-reardirection of the vehicle. The transmission 11 is arranged at the left ofthe engine 10 in FIG. 3. A cut-out portion 12 b, which will be describedbelow, is formed at an upper portion of a back wall portion 12 a of atransmission case 12. The forward portion of the left side frame 13 ofthe left and right side frames 13, whose forward portion is upwardlycurved for avoiding interference with a front axle, extends through thecut-out portion 12 b formed at an upper portion of the back wall portion12 a of the transmission case 12.

As illustrated in FIGS. 1 and 2, the transmission 11 includes an inputshaft 15 rotatably driven by the engine 10, an output shaft 19 connectedto driving wheels (not shown), first and second counter shafts 16 and 17and a reverse shaft 18 that are arranged parallel to the input shaft 15and that are connected to the output shaft 19 via a reduction gear set28 a, 28 b, 28 c and 28 d, a first forward movement gear switching unit20A (a first gear mechanism) arranged between the input shaft 15 and thefirst counter shaft 16, a second forward movement gear switching unit20B (a second gear mechanism) and a third forward movement gearswitching unit 20C (a third gear mechanism) each of which is arrangedbetween the input shaft 15 and the second counter shaft 17, a reversemovement gear switching unit 20D arranged between the input shaft 15 andthe reverse shaft 18, and the transmission case 12. The transmissioncase 12 supports the input shaft 15, the first and second counter shaft16 and 17, the reverse shaft 18, the output shaft 19, the first, second,and third forward movement gear switching units 20A, 20B, 20C and areduction gear set 28 a, 28 b, 28 c and 28 d, most of which areaccommodated therewithin. The reduction gear set 28 a, 28 b, 28 c and 28d is arranged at a position which is the closest to the engine 10 amongthe gear sets within the transmission case 12. The first, second andthird forward movement gear switching units 20A, 20B and 20C and thereverse movement switching unit 20 D are positioned so as to be moredistant from the engine 10 relative to the reduction gear set 28 a, 28b, 28 c and 28 d.

As illustrated in FIGS. 1 and 3, the transmission 11 is arranged at oneside of the engine 10 so as to be connected therewith in the axialdirection of the engine 10. The transmission case 12 is fixed to theengine 10. A left end portion and a middle portion of the input shaft 15in FIG. 1 is rotatably supported at the transmission case 12, and aright end portion of the input shaft 15 is connected to a crank shaft(not shown) of the engine 10 via a clutch (not shown). Both ends of eachof the first counter shaft 16, the second counter shaft 17 and thereverse shaft 18 are rotatably supported at the transmission case 12.The output shaft 19 is formed with a first shaft 19 a and a second shaft19 b that are coaxially connected via a differential mechanism 29arranged within the transmission case 12. The first and second shafts 19a and 19 b are rotatably supported by the transmission case 12. Further,each outer end portion of each of the first and second shafts 19 a and19 b is connected to the corresponding driving wheel via a joint and adrive shaft (not shown). The smaller reduction gears 28 a, 28 b and 28 cfixed at the first and second counter shafts 16 and 17 and the reverseshaft 18, respectively, engage with the reduction larger gear 28 d,having a larger diameter than the reduction gears 27 a, 28 b and 28 cand provided at the differential mechanism 29, thereby connecting thefirst and second counter shafts 16 and 17 and the reverse shaft 18 tothe output shaft 19. ‘Small’, as used in the reduction small gears 28 a,28 b and 28 c, does not refer to specific size thereof, but ratherbecause sizes of the reduction gears 28 a, 28 b, and 28 c are smallerthan the reduction gear 28 d. Similarly, ‘large’, as used in thereduction large gear 28 d, does not refer to a specific size thereof,but rather because a size of the reduction gear 28 d is larger thanother reduction gears 28 a, 28 b and 28 c. Additionally, as illustratedin FIG. 2, the second counter shaft 17 and the reverse shaft 18 arepositioned above the input shaft 15 and the first counter shaft 16 inthis embodiment.

As illustrated in FIG. 1, the first forward movement gear switching unit20A is arranged at a position relatively close to the engine 10. Thesecond forward movement gear switching unit 20B is arranged at anposition more distant from the engine 10 relative to the first movementgear switching unit 20A. The first forward movement gear switching unit20A forms a 1st shift stage and a 2nd shift stage, and includes twopairs of gear sets arranged between the input shaft 15 and the firstcounter shaft 16, i.e. a 1st shift stage gear set (first gear set) 21 a,21 b and a 2nd shift stage gear set (second gear set) 22 a, 22 b, and afirst switching clutch 30A. The 1st shift stage gear set includes thedriving gear 21 a and the driven gear 21 b, and the 2nd shift stage gearset includes the driving gear 22 a and the driven gear 22 b. The firstswitching clutch 30A is arranged between the 1st shift stage gear set 21a, 22 b and the 2nd shift stage gear set 22 a, 22 b, and establishes apower (torque) transmission established by each of the 1st shift stagegear set 21 a, 22 b and the 2nd shift stage gear set 22 a, 22 b betweenthe input shaft 15 and the first counter shaft 16. The driving gear 21 aof the 1st shift stage gear set 21 a and 21 b and a driving gear 22 a ofthe 2nd shift stage gear set 22 a and 22 b are fixed at the input shaft15, and the driven gear 21 b of the 1st shift stage gear set 21 a and 21b and the driven gear 22 b of the 2nd shift stage gear set 22 a and 22 bare rotatably provided at the first counter shaft 16. The firstswitching clutch 30A is provided between the driven gears 21 b and 22 b,and selectively connects either one of the driven gears 21 b and 22 bwith rotation of the first counter shaft 16.

A known synchromesh mechanism is adapted to the first switching clutch30A. The first switching clutch 30A incorporates therein a clutch hub L,fixed at the first counter shaft 16, a sleeve M spline-engaged with anouter periphery of the clutch hub L so as to be movable in an axialdirection of the first counter shaft 16, and engaging members S1 and S2that are integrally formed at the driven gears 21 b and 22 b,respectively and that are spline-engageable with the sleeve M. When thesleeve M of the first switching clutch 30A is shifted towards the drivengear 21 b by means of a manually or automatically operated shift fork Nfrom a neutral position illustrated in FIG. 1, the sleeve M isspline-engaged with the engaging member S1, and the driven gear 21 b ofthe 1st shift stage gear set 21 a and 21 b is connected to the rotationof the first counter shaft 16. As a result, the 1st shift stage isestablished. Further, when the sleeve M is shifted towards the drivengear 22 b by means of the shift fork N from the position where the 1stshift stage is established, firstly the engaging member S1 is disengagedfrom the sleeve M, and the sleeve M is returned to the neutral position.When the sleeve M is shifted further towards the driven gear 22 b, thesleeve M is spline-engaged with the engaging member S2, and the drivengear 22 b of the 2nd shift stage gear set 22 a and 22 b is connected tothe rotation of the first counter shaft 16. As a result, the 2nd shiftstage is established. When the sleeve M is shifted towards the drivengear 21 b from the position where the 2nd shift stage is established,the sleeve M is returned to the neutral position.

The second forward movement gear switching unit 20B forms a 3rd shiftstage and a 4th shift stage, and includes a 3rd shift stage gear set(third gear set) 23 a, 23 b and a 4th shift stage gear set (fourth gearset) 24 a, 24 b, both of which are arranged between the input shaft 15and the first counter shaft 16, and a second switching clutch 30Barranged between the 3rd and second 4th stage gear sets. The 3rd shiftstage gear set includes the driving gear 23 a and the driven gear 23 b,and the 4th shift stage gear set includes the driving gear 24 a and thedriven gear 24 b. The second forward movement gear switching unit 20B isstructured substantially the same as the first forward movement gearswitching unit 20A. When a sleeve M of the second switching clutch 30Bis shifted towards the driven gear 23 b of the 3rd shift stage gear set23 a and 23 b from a neutral position illustrated in FIG. 1, the 3rdshift stage is established by the substantially same manner as, forexample, the 2nd shift stage is established. When the sleeve M isshifted towards the driven gear 24 b of the 4th shift stage gear set 24a and 24 b from the position where the 3rd shift stage is established,the sleeve M is returned to the neutral position. When the sleeve M isfurther shifted towards the driven gear 24 b from the neutral position,the 4th shift stage is established. Further, when the sleeve M isshifted towards the driven gear 23 b from the position where the 4thshift stage is established, the sleeve M is returned to the neutralposition.

As is the case with the first forward movement gear switching unit 20A,the third forward movement gear switching unit 20C is arranged at aposition relatively close to the engine 10. The third forward movementgear switching unit 20C forms a 5th shift stage and a 6th shift stage,and includes a 5th shift stage gear set (fifth gear set) 25 a, 25 b anda 6th shift stage gear set (sixth gear set) 26 a, 26 b, both of whichare arranged between the input shaft 15 and the second counter shaft 17,and a third switching clutch 30C arranged between the 5th and 6th shiftstage gear sets. The 5th shift stage gear set includes the driving gear25 a and the driven gear 25 b, and the 6th shift stage gear set includesthe driving gear 26 a and the driven gear 26 b. The third forwardmovement gear switching unit 20C is structured substantially the same asthe first and second forward movement gear switching units 20A and 20B.When a sleeve M of the third switching clutch 30C is shifted towards thedriven gear 25 b of the 5th shift stage gear set 25 a and 25 b from aneutral position illustrated in FIG. 1, the 5th shift stage isestablished by the substantially same manner as, for example, the 1stshift stage is established. When the sleeve M is shifted towards thedriven gear 26 b of the 6th shift stage gear set 26 a and 26 b from theposition where the 5th shift stage is established, the sleeve M isreturned to the neutral position. When the sleeve M is further shiftedtowards the driven gear 26 b from the neutral position, the 6th shiftstage is established. Further, when the sleeve M is shifted towards thedriven gear 25 b from the position where the 6th shift stage isestablished, the sleeve M is returned to the neutral position.

The driving gear 25 a of the 5th shift stage gear set 25 a and 25 b,arranged at the position more distant from the engine 10 at the thirdforward movement gear switching unit 20C relative to the driven gear 26a, is fixed at the input shaft 15 and serves also as the driving gear 24a of the fourth shift stage gear set 24 a and 24 b, arranged at theposition close to the first forward movement gear switching unit 20A atthe second forward movement gear switching unit 20B relative to thedriven gear 23 a. The driving gear 26 a of the 6th shift stage gear set26 a and 26 b, arranged at the position close to the engine 10 at thethird forward movement gear switching unit 20C relative to the 5th shiftstage gear set 25 a and 25 b, is fixed at the input shaft 15 so as to bearranged between the driving gear 21 a of the 1st shift stage gear set21 a, 21 b and the driving gear 22 a of the 2nd shift stage gear set 22a, 22 b of the first forward movement gear switching unit 20A.

As illustrated in FIGS. 1 and 2, the reverse movement gear switchingunit 20D forms a reverse movement shift stage and is arranged at aposition close to the engine 10 relative to a reverse movement switchingclutch 30D as is the case with the first forward movement gear switchingunit 20A. The reverse movement gear switching unit 20D includes areverse gear set 27, arranged between the input shaft 15, the firstcounter shaft 16 and the reverse shaft 18, and the reverse movementswitching clutch 30D is configured to establish a power transmissionpath established by the reverse gear set 27 between the input shaft 15and the reverse shaft 18. The reverse gear set 27 is formed with adriving gear 27 a, an idler gear 27 b and a driven gear 27 c that arearranged between the third forward movement gear switching unit 20C andthe reduction gear set 28 a, 28 b, 28 c and 28 d. The driving gear 27 aserves also as the driving gear 21 a of the 1st shift stage gear set 21a and 21 b. Further, the idler gear 27 b is rotatably supported at thesecond counter shaft 17. The driven gear 27 c is rotatably supported atthe reverse shaft 18. The reverse movement switching clutch 30D isprovided at the reverse movement shaft 18 so as to be arranged inparallel to driven gear 27 c so as to establish a power transmissionpath between the driven gear 27 c and the reverse shaft 18. The reversemovement switching clutch 30D has substantially the same structure asthe first switching clutch 30A except that the reverse movementswitching clutch 30D includes only an engaging member SR fixed at thedriven gear 27 c, arranged at one side of the reverse movement switchingclutch 30D, in an axial direction of the reverse shaft 18. When a sleeveM of the reverse movement switching clutch 30D is shifted towards thedriven gear 27 c from a neutral position illustrated in FIG. 1 by meansof a shift fork N, the sleeve M is spline-engaged with the engagingmember SR, and the driven gear 27 c of the reverse gear set 27 isconnected to the reverse shaft 18. As a result, a reverse shift stage isestablished. When the sleeve M is shifted in a reverse direction to beaway from the driven gear 27 c at the state where the reverse shiftstage is established, the sleeve M is disengaged from the engagingmember SR, and the reverse shift stage is cancelled.

In the above-described embodiment, the first forward movement gearswitching unit 20A, the third forward movement gear switching unit 20Cand the reverse movement gear switching unit 20D are arranged at thepositions relatively close to the engine 10 within the transmission case12 and the second forward movement gear switching unit 20C is arrangedat a position more remote from the engine 10 relative to the firstforward movement gear switching unit 20A. Further, a length of thereverse movement switching unit 20D in the axial direction is defined tobe shorter than a length of the third forward movement gear switchingunit 20C in the axial direction because the reverse movement switchingunit 20D includes the driven gear 27 c at only one side of the reversemovement switching clutch 30D while the third forward movement gearswitching unit 20C includes the driven gears 25 b and 26 b at both sidesof the forward movement switching clutch 30C. Therefore, among endportions which are spaced from the engine 10 of each of the secondforward movement gear switching unit 20B, the third forward movementgear switching unit 20C and the reverse movement gear switching unit20D, the end portion of the second forward movement gear switching unitis arranged to be farthest from the engine 10 and the end portion of thereverse movement gear switching unit 20D is arranged closest to theengine 10 in the axial direction of the input shaft 15. Further, thesecond counter shaft 17, at which the driven gear 25 b and 26 b of thethird forward movement gear switching unit 20C and the third switchingclutch 30C are provided, is arranged above the input shaft 15, at whichthe first forward movement switching unit 20A and the second forwardmovement switching unit 20B are provided, and above the first countershaft 16. The reverse shaft 18, at which the driven gear 27 c of thereverse movement gear switching unit 20D and the reverse movement gearswitching clutch 30D are provided, is arranged further above the inputshaft 15 than the second counter shaft 17. As illustrated in FIGS. 1 and3 the transmission case 12 forms the cut-out portion 12 b at the backwall portion 12 a thereof.

Hence, as illustrated in FIG. 3, in a case where the transmission 11 andthe engine 10 are arranged in the axial direction thereof so as to beintegrally connected with each other and then the integrally and axiallyconnected transmission 11 and engine 10 is transversely mounted at theforward portion of the vehicle body, the upwardly curved forward portionof one of the right and left side frames 13, serving as the strengthmember, is arranged so as to extend through the cut-out portion 12 b ofthe transmission case 12. As a result, even in a case where axiallyconnected transmission 11 and the engine 10 of the embodiment is adaptedto a vehicle having side frames having the enlarged cross-sectionalshapes and linearized linearized shapes, as illustrated in FIG. 3, oneof the side frames 13 is prevented from interfering with thetransmission case 12 because the one of the side frames 13 extendsthrough the cut-out portion 12 b of the transmission case 12, comparedto a case where the conventional transmission 1 interfered with one ofthe side frames 9 a having the enlarged cross-sectional shapes andlinearized shapes when then conventional transmission 1 and the engine10 are axially connected and transversely mounted on the vehicle body,as illustrated in FIG. 5 Hence, the axially connected transmission 11and engine 10 is transversely mountable on the vehicle body withoutcausing interference between one of the side frames 13 and thetransmission case 12.

In the above-described embodiment, the driving gear 25 a of the 5thshift stage gear set 25 a and 25 b, arranged more distant from theengine 10 at the third forward movement gear switching unit 20C relativeto the 6th shift stage gear set 26 a, 26 b, serves also as the drivinggear 24 a of the 4th shift stage gear set 24 a and 24 b, arranged at thesecond forward movement gear switching unit 20B which is arranged closerto the first forward movement gear switching unit 20A at the secondforward movement gear switching unit 20B. The driving gear 26 a of the6th shift stage gear set 26 a and 26 b, positioned close to the engineat the third forward movement gear switching unit 20C relative to the5th shift stage gear set, is fixed at the input shaft 15 between thedriving gears 21 a of the 1st shift stage gear set 21 a, 21 b and thedriving gear 22 a of the 2nd shift stage gear set 22 a, 22 b. Thedriving gear 26 a does not serve as the driving gear 21 a. As a result,one of the plural gears at the plural forward movement shift stage gearsets, 21 a and 21 b, 22 a and 22 b, 23 a and 23 b, and 24 a and 24 b,provided between the input shaft 15 and the first counter shaft 16 iseliminated by one gear serving as driving gears of two forward movementshift stages, and similarly, one of the plural gears at the plural shiftstage gear sets, 25 a and 25 b, and 26 a and 26 b, provided between theinput shaft 15 and the second counter shaft 17, is eliminated by onegear serving as driving gears of two forward movement shift stages.Therefore, the structure of the transmission 11 is simplified, andlength of the input shaft 15 and the counter shaft 16 are shortened.Further, instead of serving also as the driving gear 24 a, the drivinggear 25 a may serve also as the driving gear 22 a. Even in the casewhere the driving gear 25 a of the 5th shift stage gear set 25 a and 25b serves also as the driving gear 22 a of the 2nd shift stage gear set22 a and 22 b, the same effects and advantages are achieved. In thiscase, the length of the second counter shaft 17 is further shortenedrelative to the input shaft 15 and first counter shaft 16.

The embodiment above describes the transmission having the reversemovement gear switching unit 20D. However, the present inventiondescribed in the embodiment is adaptable to a transmission not having areverse movement gear switching unit. Even in a case where the presentinvention is adapted to the transmission not having the reverse movementgear switching unit, most of the effects and advantages described abovein the embodiment will be achieved.

Further, in the transmission 11 of the first and second embodiments, thefirst forward movement gear switching unit 20A includes the 1st shiftstage gear set 21 a, 21 b, the 2nd shift stage gear set 22 a, 22 b andthe first switching clutch 30A that is provided therebetween andestablishes the power transmission path established by each of the 1stshift stage gear set 21 a, 21 b and the 2nd shift stage gear set 22 a,22 b between the input shaft 15 and the first counter shaft 16, thesecond forward movement gear switching unit 20B includes the 3rd shiftstage gear set 23 a, 23 b, the 4th shift stage gear set 24 a, 24 b andthe second switching clutch 30B that is provided therebetween andestablishes the power transmission path established by each of the 3rdshift stage gear set 23 a, 23 b and the 4th shift stage gear set 24 a,24 b between the input shaft 15 and the first counter shaft 16, and thethird forward movement gear switching unit 20C includes the 5th shiftstage gear set 25 a, 25 b, the 6th shift stage gear set 26 a, 26 b andthe third switching clutch 30C that is provided therebetween andestablishes the power transmission path established by each of the 5thshift stage gear set 25 a, 25 b and the 6th shift stage gear set 26 a,26 b between the input shaft 15 and the second counter shaft 17.Accordingly, the transmission 11 is structured to have six shift stageswhich is a maximum number of shift stages for a transmission havingthree forward movement gear switching units. Hence, output torque of thetransmission 11 is increased. The present invention is not limited tothe above-described embodiment, but one or more of the first, second andthird forward movement gear switching units 20A, 20B and 20C may includeonly one forward movement shift stage gear set.

In the above-described embodiment, the first forward movement shiftstage gear set is assigned as the 1st shift stage gear set 21 a and 21b, the second forward movement shift stage gear set is assigned as the2nd shift stage gear set 22 a and 22 b, the third forward movement shiftstage gear set is assigned as the 3rd shift stage gear set 23 a and 23b, the fourth forward movement shift stage gear set is assigned as the4th shift stage gear set 24 a and 24 b, the fifth forward movement shiftstage gear set is assigned as the 5th shift stage gear set 25 a and 25b, and the sixth forward movement shift stage gear set is assigned asthe 6th shift stage gear set 26 a and 26 b. However, each shift stagemay be assigned at any desired forward movement shift stage gear setarranged at the positions illustrated in FIGS. 1 and 2.

Further, the axially connected transmission 11 and the engine 10,adapted to the front-engine front-drive type vehicle, is describedabove. The present invention is not limited to be adapted to thefront-engine front-drive type vehicle, but the present invention is alsoadaptable to a rear-engine rear-drive type vehicle.

Accordingly, the first forward movement gear switching unit 20A and thethird forward movement gear switching unit 20C are arranged relativelyclose to the engine 10 within the transmission case 12, and the secondforward movement gear switching unit 20B is arranged more distant fromthe engine 10 relative to the first forward movement gear switching unit20A. The second counter shaft 17 is arranged above the input shaft 15and the first counter shaft 16. As a result, the transmission case 12,located at the more distant side of the engine 10, is formed to have thefirst back wall portion 12 a 1 corresponding to the first and secondforward movement gear switching units 20A and 20B and the second backwall portion 12 a 2 corresponding to a portion of the third forwardmovement gear switching unit 20C, wherein the second back wall portion12 a 2 is located closer to the engine 10 than the first back wallportion 12 a 1 arranged below the second back wall portion 12 a 2. As aresult, the transmission case 12 forms the cut-out portion 12 b at theupper portion of the back wall 12 a. By adapting the above-structuredtransmission 11, the transmission 11 and the engine 10 are connected inthe axial direction thereof, and the axially connected transmission 11and engine 10 is transversely mounted on the vehicle body so that one ofthe side frames 13, extending along the both sides of the vehicle bodyin the front-rear direction thereof, extends through the cut-out portion12 a of the transmission case 12. As a result, even in a case whereaxially connected transmission 11 (11′) and the engine 10 of the firstembodiment is adapted to a vehicle having side frames having theenlarged cross-sectional shapes and linearlized shapes, as illustratedin FIG. 3, one of the side frames 13 is prevented from interfering withthe transmission case 12 because the one of the side frames 13 extendsthrough the cut-out portion 12 b of the transmission case 12, comparedto a case where the conventional transmission 1 interferes with the oneof the side frames 9 a. Hence, the axially connected transmission 11 andengine 10 is transversely mountable on the vehicle body without causingthe interference between one of the side frames 13 and the transmissioncase 12. Further, as the driving gear 25 a of the 5th shift stage gearset 25 a and 25 b arranged more distant from the engine 10 at the thirdforward movement gear switching unit 20D relative to the 6th shift stagegear set 26 a and 26 b is fixed at the input shaft 15 and serves also asthe driving gear 22 a of the 2nd shift stage gear set 22 a and 22 barranged close to the second forward gear switching unit 20B at thefirst forward gear switching unit 20A or the driving gear 24 a of the4th shift stage gear set 24 a and 24 b arranged close to the firstforward movement gear switching unit 20A at the second forward gearswitching unit 20B, one of the driving gears is eliminated. As a result,the structure of the transmission 11 is simplified and the transmission11 is downsized.

According to the embodiments, the transmission 11 transversely mountedon the vehicle includes a reverse movement gear switching unit 20Dincluding a reverse shaft 18 arranged in parallel to the input shaft 15and connected to the output shaft 19, a reverse gear set 27 providedbetween the input shaft 15 and the reverse shaft 18 and a reversemovement switching clutch 30D establishing a power transmission pathestablished by the reverse gear set 27 between the input shaft 15 andthe reverse shaft 18, wherein the 1st shift stage gear set 21 a, 21 barranged more distant from the engine 10 relative to the 2nd shift stagegear set 22 a, 22 b is set as a gear set for a low speed shift stage,the reverse gear set 20D includes a driving gear 27 a provided at theinput shaft 15, an idler gear 27 b rotatably supported at the firstcounter shaft 16 or the second counter shaft 17 and a driven gear 17 crotatably provided at the reverse shaft 18 wherein the driving gear 27 aof the reverse gear set serves also as a driving gear 21 a of the 1stshift stage gear set 21 a, 21 b of first forward movement gear switchingunit 20A, arranged closer to the engine 10 relative to the 2nd shiftstage gear set 22 a, 22 b.

Accordingly, the transmission 11 further includes the reverse shaft 18arranged in parallel to the input shaft 15 and connected to the outputshaft 19, and the reverse movement gear switching unit 20D providedbetween the input shaft 15 and the reverse shaft 18 and formed with thepair of the reverse gear set 27 and the reverse movement switchingclutch 30D that is configured to establish the power transmission pathestablished by the reverse gear set 27 between the input shaft 15 andthe reverse shaft 18. The forward movement shift stage gear set 21 a and21 b of the first forward movement gear switching unit 20A arranged moredistant from the engine 10 is a gear set for low speed shift stage. Thereverse gear set 27 is formed with the driving gear 27 a provided at theinput shaft 15, the driven gear 27 c rotatably supported at the reverseshaft 18 and and the idler gear 27 b rotatably supported at the secondcounter shaft 17 and engaged with the driving gear 27 a and the drivengear 27 c. The driving gear 27 a of the reverse gear set 27 serves alsoas the driving gear 21 a of the first shift stage gear set 21 a and 21 bof the first forward movement gear switching unit 20A which is arrangedclose to the engine 10 relative to the second forward movement gearswitching unit 20B. Accordingly, the reverse movement gear switchingunit 20D provided at the input shaft 15, the first counter shaft 16 andthe reverse shaft 18 is arranged close to the engine 10 substantially inthe same manner as the first and third gear switching units 20A and 20C.Therefore, the second back wall portion 12 a 2 of the back wall portion12 a of the transmission case 12 is arranged closer to the engine 10than the first back wall portion 12 a 1 of the back wall portion 12 a ofthe transmission case 12 so as to form the cut-out portion 12 b at ofthe upper back wall portion 12 a of the transmission case 12. Therefore,even in the case where the reverse movement gear switching unit 20D isprovided within the transmission case 12, one of the side frames 13 isprovided so as to extend through the cut-out portion 12 b in thefront-rear direction of the vehicle, so that one of the side frames 13does not interfere with the transmission case 12. As a result, theaxially connected engine 10 and transmission 11 is transverselymountable on the vehicle body. As the driving gear 21 a of the 1st shiftstage gear set 21 a and 21 b of the first forward movement gearswitching unit 20A, serving also as the driving gear 27 a of the reversegear set 27, is the gear of the low speed shift stage, the reductiongear ratio of the reverse gear set 27 is easily increased.

According to the embodiment the first forward movement gear switchingunit 20A includes the 1st shift stage gear set, 21 a, 21 b, the 2ndshift stage gear set 22 a, 22 b, and the first switching clutch arrangedtherebetween and establishing the power transmission path established byeach of the 1st shift stage gear set 21 a, 21 b and the 2nd shift stagegear set 22 a, 22 b between the input shaft 15 and the first countershaft 16, the second forward movement gear switching unit 20B includesthe 3rd shift stage gear set 23 a, 23 b, the 4th shift stage gear set 24a, 24 b and the second switching clutch 30B arranged therebetween andestablishing the power transmission path established by each of the 3rdshift stage gear set 23 a, 23 b and the 4th shift stage gear set 24 a,24 b between the input shaft 15 and the first counter shaft 16, and thethird forward movement gear switching unit 20C includes the 5th shiftstage gear set 25 a, 25 b, the 6th shift stage gear set 26 a, 26 b, andthe third switching clutch 30C arranged therebetween and establishingthe power transmission path established by each of the 5th shift stagegear set 25 a, 25 b and the 6th shift stage gear set 26 a, 26 b betweenthe input shaft 15 and the second counter shaft 17.

Accordingly, the first forward movement gear switching unit 20A includesthe 1st shift stage gear set 21 a, the 2nd shift stage gear set 22 a 22b, and the first switching clutch 30A arranged therebetween andestablishes the power transmission path established by each of the 1stshift stage gear set 21 a, 21 b and the 2nd shift stage gear set 22 a,22 b between the input shaft 15 and the first counter shaft 16, thesecond forward movement gear switching unit 20B includes the 3rd shiftstage gear set 23 a, 23 b, the 4th shift stage gear set 24 a 24 b, andthe second switching clutch 30B arranged therebetween and establishesthe power transmission path established by each of the 3rd shift stagegear set 23 a, 23 b and the 4th shift stage gear set 24 a, 24 b betweenthe input shaft 15 and the first counter shaft 16 and the third forwardmovement gear switching unit 20C includes the 5th shift stage gear set25 a, 25 b, the 5th shift stage gear set 26 a 26 b, and the thirdswitching clutch 30C arranged therebetween and establishes the powertransmission path established by each of the 5th shift stage gear set 25a, 25 b and the 6th shift stage gear set 26 a, 26 b between the inputshaft 15 and the second counter shaft 17. Hence, the transmission 11 isstructured to have six shift stages which is a maximum number of shiftstages for a transmission having three forward movement gear switchingunits.

The principles, preferred embodiment and mode of operation of thepresent invention have been described in the foregoing specification.However, the invention which is intended to be protected is not to beconstrued as limited to the particular embodiments disclosed. Further,the embodiments described herein are to be regarded as illustrativerather than restrictive. Variations and changes may be made by others,and equivalents employed, without departing from the sprit of thepresent invention. Accordingly, it is expressly intended that all suchvariations, changes and equivalents which fall within the spirit andscope of the present invention as defined in the claims, be embracedthereby.

1. A vehicle comprising: an engine; a pair of side frames provided atthe vehicle so as to extend along both sides of a vehicle body infront-rear direction of the vehicle; a transmission adapted to beaxially connected with the engine and adapted to be transversely mountedon a vehicle body, comprising: an input shaft adapted to be rotatablydriven by the engine; an output shaft connected to a driving wheel; afirst counter shaft arranged in parallel to the input shaft andconnected to the output shaft; a second counter shaft arranged inparallel to the input shaft and connected to the output shaft; a firstgear mechanism arranged between the input shaft and the first countershaft, the first gear mechanism having a first gear set, optionally asecond gear set, and a first switching clutch to selectively establish apower transmission path between the input shaft and the first countershaft via the first gear set or, if present the second gear set; asecond gear mechanism provided between the input shaft and the firstmechanisms extending counter shaft, the second and first gear parallelto one another between the input shaft and the first counter shaft, thesecond gear mechanism having a third gear set, optionally a fourth gearset, and a second switching clutch selectively establish a powertransmission path between the input shaft and the first counter shaftvia the third gear set or, if present the fourth gear set; a third gearmechanism between the input shaft and the second counter shaft, thethird gear mechanism having a fifth gear set, optionally a sixth gearset, and a third switching clutch to selectively establish a powertransmission path between the input shaft and the second counter shaftvia the fifth gear set or, if present the sixth gear set; and atransmission case supporting and covering the input shaft, the firstcounter shaft, the second counter shaft, the output shaft, the firstgear mechanism, the second gear mechanism and the third gear mechanism;wherein the first gear mechanism and the third gear mechanism arearranged relatively close to the engine, the second gear mechanism isarranged at a position more distant from the engine than the first gearmechanism, and the second counter shaft is arranged above the inputshaft and the first counter shaft, and the transmission case includes aback wall portion located at a position spaced from the engine andformed with a first back wall portion aligned with the first gearmechanism and the second gear mechanism and a second back wall portioncorresponding to the third mechanism and located closer to the enginethan the first back wall portion, thereby forming a cut-out portion atan upper portion of the back wall portion, and wherein the transmissionis connected to the engine and transversely mounted on the vehicle bodyso that one of side frames extending along both sides of the vehiclebody in a front-rear direction thereof extends through the cut-outportion, either a driving gear of the second gear set arranged close tothe second gear mechanism relative to the first gear set at the firstgear mechanism and provided at the input shaft, or a driving gear of thefourth gear set arranged close to the first gear mechanism relative tothe third gear set at the second gear mechanism and provided at theinput shaft serves also as a driving gear of the fifth gear set arrangedat a position more distant from the engine relative to the sixth gearset at the third gear mechanism.
 2. The vehicle according to claim 1,further comprising: a reverse movement gear switching unit including areverse shaft arranged in parallel to the input shaft and connected tothe output shaft, a reverse gear set provided between the input shaftand the reverse shaft and a reverse movement switching clutch forselectively establishing a power transmission path via the reverse gearset between the input shaft and the reverse shaft, wherein the firstgear set is arranged more distant from the engine than the second gearset and is a gear set for a low speed shift stage, the reverse gear setincludes a driving gear provided at the input shaft, an idler gearrotatably supported at the first counter shaft or the second countershaft and a driven gear rotatably provided at the reverse shaft whereinthe driving gear of the reverse gear set serves also as a driving gearof the first gear set of first gear mechanism, the first gear set of thefirst gear mechanism arranged closer to the engine relative to thesecond gear set.
 3. The vehicle according to claim 1, wherein the firstgear mechanism includes the first gear set, the second gear set and thefirst switching clutch arranged therebetween for selectivelyestablishing a first or a second speed range power transmission pathbetween the input shaft and the first counter shaft, the second gearmechanism includes the third gear set, the fourth gear set and thesecond switching clutch arranged therebetween and for selectivelyestablishing a third or a fourth speed range power transmission pathbetween the input shaft and the first counter shaft, and the third gearmechanism includes the fifth gear set, the sixth gear set and the thirdswitching clutch arranged therebetween for selectively establishing afifth or a sixth speed range power transmission path between the inputshaft and the second counter shaft.
 4. The vehicle according to claim 2,wherein: the first gear mechanism includes the first gear set, thesecond gear set and the first switching clutch arranged therebetween forselectively establishing a first or a second speed range powertransmission path between the input shaft and the first counter shaft,the second gear mechanism includes the third gear set, the fourth gearset and the second switching clutch arranged therebetween and forselectively establishing a third or a fourth speed range powertransmission path between the input shaft and the first counter shaft,and the third gear mechanism includes the fifth gear set, the sixth gearset and the third switching clutch arranged therebetween for selectivelyestablishing a fifth or a sixth speed range power transmission pathbetween the input shaft and the second counter shaft.
 5. A transmissionadapted to be axially connected with the engine and adapted to betransversely mounted on a vehicle body, comprising: an input shaftadapted to be rotatably driven by the engine; an output shaft connectedto a driving wheel; a first counter shaft arranged in parallel to theinput shaft and connected to the output shaft; a second counter shaftarranged in parallel to the input shaft and connected to the outputshaft; a first gear mechanism arranged between the input shaft and thefirst counter shaft, the first gear mechanism having a first gear set,optionally a second gear set, and a first switching clutch toselectively establish a power transmission path between the input shaftand the first counter shaft via the first gear set or, if present thesecond gear set; a second gear mechanism provided between the inputshaft and the first counter shaft, the second and first gear mechanismsextending parallel to one another between the input shaft and the firstcounter shaft, the second gear mechanism having a third gear set,optionally a fourth gear set, and a second switching clutch selectivelyestablish a power transmission path between the input shaft and thefirst counter shaft via the third gear set or, if present the fourthgear set; a third gear mechanism between the input shaft and the secondcounter shaft, the third gear mechanism having a fifth gear set,optionally a sixth gear set, and a third switching clutch to selectivelyestablish a power transmission path between the input shaft and thesecond counter shaft via the fifth gear set or, if present the sixthgear set; and a transmission case supporting and covering the inputshaft, the first counter shaft, the second counter shaft, the outputshaft, the first gear mechanism, the second gear mechanism and the thirdgear mechanism; wherein the first gear mechanism and the third gearmechanism are arranged relatively close to the engine, the second gearmechanism is arranged at a position more distant from the engine thanthe first gear mechanism, and the second counter shaft is arranged abovethe input shaft and the first counter shaft, and the transmission caseincludes a back wall portion located at a position spaced from theengine and formed with a first back wall portion aligned with the firstgear mechanism and the second gear mechanism and a second back wallportion corresponding to the third gear mechanism and located closer tothe engine than the first back wall portion, thereby forming a cut-outportion at an upper portion of the back wall portion, and wherein thetransmission is connected to the engine and transversely mounted on thevehicle body so that one of side frames extending along both sides ofthe vehicle body in a front-rear direction thereof extends through thecut-out portion, either a driving gear of the second gear set arrangedclose to the second gear mechanism relative to the first gear set at thefirst gear mechanism and provided at the input shaft, or a driving gearof the fourth gear set arranged close to the first gear mechanismrelative to the third gear set at the second gear mechanism and providedat the input shaft serves also as a driving gear of the fifth gear setarranged at a position more distant from the engine relative to thesixth gear set at the third gear mechanism.
 6. The transmissionaccording to claim 5, further comprising: a reverse movement gearswitching unit including a reverse shaft arranged in parallel to theinput shaft and connected to the output shaft, a reverse gear setprovided between the input shaft and the reverse shaft and a reversemovement switching clutch for selectively establishing a powertransmission path via the reverse gear set between the input shaft andthe reverse shaft, wherein the first gear set is arranged more distantfrom the engine than the second gear set and is a gear set for a lowspeed shift stage, the reverse gear set includes a driving gear providedat the input shaft, an idler gear rotatably supported at the firstcounter shaft or the second counter shaft and a driven gear rotatablyprovided at the reverse shaft wherein the driving gear of the reversegear set serves also as a driving gear of the first gear set of firstgear mechanism, the first gear set of the first gear mechanism arrangedcloser to the engine relative to the second gear set.
 7. Thetransmission according to claim 5, wherein: the first gear mechanismincludes the first gear set, the second gear set and the first switchingclutch arranged therebetween and for selectively establishing a first ora second speed range power transmission path between the input shaft andthe first counter shaft, the second gear mechanism includes the thirdgear set, the fourth gear set and the second switching clutch arrangedtherebetween and for selectively establishing a third or a fourth speedrange power transmission path between the input shaft and the firstcounter shaft, and the third gear mechanism includes the fifth gear set,the sixth gear set and the third switching clutch arranged therebetweenfor selectively establishing a fifth or a sixth speed range powertransmission path between the input shaft and the second counter shaft.8. The transmission according to claim 6, wherein: the first gearmechanism includes the first gear set, the second gear set and the firstswitching clutch arranged therebetween for selectively establishing afirst or a second speed range power transmission path between the inputshaft and the first counter shaft, the second gear mechanism includesthe third gear set, the fourth gear set and the second switching clutcharranged therebetween and for selectively establishing a third or afourth speed range power transmission path between the input shaft andthe first counter shaft, and the third gear mechanism includes the fifthgear set, the sixth gear set and the third switching clutch arrangedtherebetween for selectively establishing a fifth or a sixth speed rangepower transmission path between the input shaft and the second countershaft.